Prior to the conception and development of the instant invention, resilient type rubber sealing members were being extensively used, in the railroad industry, to seal the annular space located between the outer surface of such push rod member and the inner surface of the cylinder wall of such railway vehicle type brake cylinder to prevent undesirable entrance of detrimental extraneous foreign materials into the interior portion of such brake cylinder.
These resilient sealing members are, also, utilized in this particular application to provide a certain degree of support to the push rod member as it is being extended out of the brake cylinder housing during a brake application of such railway vehicle.
However, the configuration of these prior art type sealing members has, on occasion, been a source of trouble in this application. One of the primary problems being encountered with these prior art type sealing members, particularly in a new style brake rigging presently being used in the railroad industry which has a greater angular displacement than the older style brake rigging, is that they often times cause the push rod member to be pushed into greater misalignment. This, in turn, can cause rather severe problems in the push rod member by setting up excessively high bending stresses.
As has generally been illustrated in FIGS. 1 and 2, of the attached drawings, such configuration of these prior art type resilient sealing members includes a relatively wide and substantially round disc-like piece of resilient material having an aperture formed through the center portion thereof, thereby forming a resilient band-like sealing member. Such sealing member exhibits a substantially uniform thickness between the inner surface and the outer surface of the band-like sealing member.
Due to this substantially uniform thickness of such sealing member and because such band-like sealing member is, normally, slightly compressed on installation into the brake cylinder, it is unable to bulge when the push rod member is deflected in a downwardly direction as it moves into a brake applying position. This inability of the sealing member to bulge is believed to be at least one of the primary reasons why such push rod member may be pushed into greater misalignment.